Noise variations in the two regions covered by LoTSS-DR2 with the coverage of the 841 individual pointing outlined. The RA-13 (top) and RA-1 (bottom) regions span 4178 and 1457 square degrees and have median rms values of 74 μJy beam⁻¹ and 106 μJy beam⁻¹ respectively. Failed facets (white regions) are generally caused by either poor ionospheric conditions or dynamic range issues around bright sources such as 3C 48 and 3C 196.